Loading unit velocity and position feedback

ABSTRACT

A loading unit for a surgical stapling device has a cartridge assembly and an anvil assembly, the cartridge assembly including a channel and a staple cartridge having a plurality of surgical staples therein. An axial drive assembly has a clamping member, the clamping member having an upper flange for engaging the anvil assembly, and a lower flange for engaging the channel. The axial drive assembly is movable through the staple cartridge to drive the staples out of the staple cartridge and against the anvil assembly. Mechanical features are defined in the channel for indicating an end of stroke for the axial drive assembly, the mechanical features having a first pattern and a second pattern.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. ProvisionalPatent Application No. 61/715,485, filed Oct. 18, 2012, the entiredisclosure of which is incorporated by reference herein.

TECHNICAL FIELD

The present disclosure is directed to surgical devices, such as surgicalstapling instruments, that have a handle portion and a removable andreplaceable end effector or loading unit. In particular, the presentdisclosure relates to surgical devices and loading units having sensorsfor identifying the type of end effector, and providing feedbackconcerning the use of the loading unit.

BACKGROUND

Surgical devices having a handle portion and a replaceable unit areknown. A surgical device that can be used to fire different types andsizes of loading units is disclosed in U.S. Pat. No. 7,044,353 to Mastriet al. (“Mastri”), the disclosure of which is hereby incorporated byreference in its entirety. In Mastri, the loading units can havedifferent sized surgical staples and, further, different staple linelengths. U.S. Pat. No. 7,565,993 to Milliman et al. disclosesarticulating and non-articulating loading units that can be used with ahandle portion, the disclosure of which is hereby incorporated byreference in its entirety.

Surgical devices having an adapter assembly and a plurality of surgicalend effectors that can be attached thereto are disclosed in U.S.Publication No. 2011-0174099, which is hereby incorporated by referencein its entirety. The adapter is used to enable a powered motorized handheld driver to connect to a variety of end effectors, such as an end toend anastomosis end effector, or circular stapler, an endoscopicgastrointestinal anastomosis end effector, such as a linear endoscopicstapler, or a transverse anastomosis end effector. Powered surgicaldevices having a remote power console have also been proposed, asdisclosed by U.S. Pat. No. 6,846,307 to Whitman et al. (“Whitman”),which is hereby incorporated by reference in its entirety. Whitmandiscloses a controller in the console for controlling the surgicaldevice. The controller can have a memory unit, including RAM and ROM,and reads data from the particular end effector attached to thecontroller. The controller can read identification data from a memoryunit on the end effector attached to the controller and then, by virtueof the controller's connection to the motors of the surgical device,control the operation of the surgical device.

A powered surgical instrument is disclosed by U.S. Pat. No. 7,887,530 toZemlok et al., the entire disclosure of which is hereby incorporated byreference herein, utilizes a shift motor to drive multiple functions ofthe instrument. A variety of sensors is disclosed.

In the context of surgical devices designed to be used with a variety ofremovable and replaceable end effectors or loading units, it isdesirable to identify the type of end effector or loading unit that isattached. This information can be used to determine how to operate thesurgical device.

SUMMARY

A loading unit for a surgical stapling device comprises a cartridgeassembly and an anvil assembly, the cartridge assembly including achannel and a staple cartridge having a plurality of surgical staplestherein. The loading unit has an axial drive assembly with a clampingmember, the clamping member having an upper flange for engaging theanvil assembly, and a lower flange for engaging the channel, the axialdrive assembly being movable through the staple cartridge to drive thestaples out of the staple cartridge and against the anvil assembly.Mechanical features are defined in the channel for indicating an end ofstroke for the axial drive assembly, the mechanical features having afirst pattern and a second pattern.

The staple cartridge of the loading unit can have a plurality of stapleretaining recesses and the surgical staples are disposed in the stapleretaining recesses. In certain embodiments, the staple retainingrecesses are arranged in linear rows. The axial drive assembly caninclude a drive beam.

In certain embodiments, a sensor is included for determining a gapbetween the anvil assembly and the cartridge assembly.

A surgical stapling device, comprising an elongate portion and a loadingunit. The loading unit comprises a cartridge assembly and an anvilassembly, the cartridge assembly including a channel and a staplecartridge having a plurality of surgical staples therein. The loadingunit has an axial drive assembly with a clamping member, the clampingmember having an upper flange for engaging the anvil assembly, and alower flange for engaging the channel, the axial drive assembly beingmovable through the staple cartridge to drive the staples out of thestaple cartridge and against the anvil assembly. Mechanical features aredefined in the channel for indicating an end of stroke for the axialdrive assembly, the mechanical features having a first pattern and asecond pattern.

The surgical stapling device can further comprise a handle portion. Thesurgical stapling device handle portion can have a motor assembly. Thesurgical stapling device can comprise a controller. The surgicalstapling device controller can be configured to determine the end ofstroke. The surgical stapling device can have the first pattern ofmechanical features with mechanical features of a different size than asize of the mechanical features of the second pattern.

The staple cartridge of the loading unit can define a longitudinal axisand staple retaining recesses arranged in linear rows along thelongitudinal axis. The channel of the cartridge assembly can define aslot. A distal end of the slot may form the end of stroke.

The second pattern of mechanical features can be closer to the distalend of the slot than the first pattern of mechanical features. Incertain embodiments, a light sensor detects the mechanical features.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the presently disclosed surgical device are disclosedherein, with reference to the following drawings:

FIG. 1 is a perspective view of the handle portion according to certainembodiments of the disclosure;

FIG. 1A is a perspective view of a handle portion and loading unitsaccording to certain embodiments of the disclosure;

FIG. 2 is a perspective view of an adapter attached to a handle portion,with some parts removed according to certain embodiments of thedisclosure;

FIG. 3 is an exploded perspective view of an adapter according tocertain embodiments of the disclosure;

FIG. 4 is a cross sectional view of part of an adapter according tocertain embodiments of the disclosure;

FIG. 5 is a perspective view of a loading unit according to certainembodiments of the present disclosure;

FIG. 6 is an axial drive assembly for a loading unit according tocertain embodiments of the present disclosure;

FIG. 7 is a detailed view of the clamping member of the axial driveassembly in accordance with certain embodiments of the presentdisclosure;

FIG. 8 is an exploded view of the loading unit according to certainembodiments of the present disclosure;

FIG. 9 is a top plan view of the loading unit according to certainembodiments of the present disclosure;

FIG. 10A is a side elevation view of a drive assembly according toembodiments of the present disclosure; and

FIG. 10B is a side elevation view of a drive assembly according toembodiments of the present disclosure.

DETAILED DESCRIPTION

Persons having skill in the art will understand the present inventionfrom reading the following description in conjunction with theaccompanying drawings. Reference characters indicate the same or similarelements throughout the drawings. As is customary, the term “distal”refers to a location farther from the user of the instrument and theterm “proximal” refers to a location that is closer to the user of theinstrument.

A surgical device having a handle portion 10, and a plurality ofremovable and replaceable loading units, is shown in FIGS. 1 through 9.The surgical device includes an elongate portion. For example, thehandle portion 10 may have an endoscopic shaft that forms part of thehandle portion 10 or the handle portion 10 may be connected to anadapter assembly 100 that includes an outer tube 106 and release button104 having a latch for removably connecting the adapter assembly to thehandle portion 10. Alternatively, the connection can be a threadedconnection, bayonet connection or any other connection. In any of theembodiments disclosed herein, a plurality of different adapters may beprovided, to work in conjunction with a plurality of different handleportions and/or a plurality of different end effectors, to provide aversatile surgical system. For example, adapter assemblies can beprovided with different length shafts, or shafts with different shapessuch as curved or straight. Adapter assemblies can be provided toconnect to different surgical end effectors, such as electrosurgicalinstruments, circular staplers, linear endoscopic staplers, etc.

The distal end of the endoscopic shaft, or the distal end of the adapterassembly 100, has a connection portion 12 for forming a connection to aloading unit. Loading units 20, 30 and 40 are shown. Although a linearendoscopic stapling loading unit 20 is described in detail, a circularstapling 30 or a transverse stapling 40 loading unit may also beattached to the surgical device. Loading units incorporating electricalenergy, ultrasonic energy, or other energy can also be provided.Appropriate adapter assemblies are provided to accommodate the variousloading units. For example, it may be desirable to provide three driveshafts for operating the circular stapling loading unit 30. An adapterassembly having three drive shafts therein could be used to separatelydrive the opening and closing of the anvil to grasp tissue, the drivingof the staples through tissue and against the anvil, and the cutting oftissue.

The adapter assembly 100 that is used with the loading unit 20 has abody 130 and two drivers: an articulation drive cable 136 and a staplingdrive cable 134. As best seen in FIG. 3, the adapter assembly 100 has adrive converter assembly for each of the drive shafts, to convertrotational motion of the output from the motor assembly 5 to lineartranslation of the drive members of the adapter assembly. For example,the first drive converter assembly 150 has a first shaft 152 thatconnects to a first output from the motor assembly 5 via the drive cable136. The first shaft 152 includes a threaded distal end 152 b. Thearticulation drive bar 154 has an internally threaded collar 154 a thatis engaged with the threaded distal end of the first shaft 152. Thethreaded distal end 154 b is long enough to translate the articulationdrive bar 154 a desired distance.

The second drive converter assembly 140 has a second shaft 148 thatconnects to a second output from the motor assembly 5, through thestapling drive cable 134. The second shaft 148 includes a threadedproximal end 148 a. An internally threaded collar 146 is engaged withthe threaded proximal end 148 a of the second shaft. The collar 146 isconnected to a tubular sleeve 144. A proximal coupling 142 connects thedrive cable 134 to the tubular sleeve 144. As the drive cable 134rotates, the tubular sleeve 144 and collar 146 are rotated and thesecond shaft 148 is advanced in a distal direction. The threadedproximal end 148 a is long enough to translate the second or staplingdrive shaft 148 a desired distance for clamping of tissue and firingstaples. In any of the embodiments disclosed herein, the drive converterassembly can have shafts that are internally threaded and thearticulation drive shaft and/or stapling drive shaft can have an endthat forms a threaded rod to engage and interact with the internallythreaded member.

The motor assembly 5 can be separate from the surgical device, but isdesirably part of the handle portion 10. One or more motors are used.For example, two dual directional motors can be mounted in the handleportion 10 and connected to a power source which may be a batteryinternal or external to the handle portion 10. It is contemplated thatthe power source can be a tethered power source such as a generator orelectrical outlet connection, and the handle can lack a battery orinclude a battery in addition to the other power source. Each motor canbe connected to a switch on the handle portion and an additional switchfor reversing the direction of the motors can be provided on the handleportion as well. The power source is desirably a removable andrechargeable direct current battery, but alternative sources, such as aremote access outlet for alternating current supply, can be used. Atransformer or gear set can be used to adapt the power source for themotors.

The distal end of the adapter assembly 100 has a connection portion 12for removably connecting to the loading unit 20. The connection portion12 may essentially form a bayonet connection, like that described inU.S. Pat. No. 7,044,353 to Mastri et al. (“Mastri”), the disclosure ofwhich is hereby incorporated by reference herein in its entirety. Alocking member 164 for securing the loading unit 20 unto the adapterassembly 100 is connected to a button 162. The button 162 is springbiased to a locked position to prevent removal of the loading unit untilthe button is moved to an unlocked position.

The endoscopic linear stapling loading unit can be like those describedin Mastri or Millman et al., U.S. Pat. No. 7,565,993, the entiredisclosures of which are hereby incorporated by reference herein. Theloading unit may also be as described in Surgical Device Identification,docket no. H-US-03725 by Joseph Taylor, filed on the same day herewith,the entire disclosure of which is hereby incorporated by referenceherein. The loading unit 20 has an elongate body portion 502 with aproximal end 650 defining two lugs 652 for forming a connection with ashaft of an adapter assembly 100 or a handle portion. Other means ofconnecting the loading unit can be used. The loading units can bedesigned to be attached to either a powered, motorized surgical driveror manually actuated handle. An end 164 a of the locking member 164 ofthe connection portion of the adapter assembly 100 (see FIG. 3) engagesthe lugs 652 of the loading unit to secure it in place. A tube 602 isdisposed around the body 502.

The loading unit 20 has an articulation link 566 with a hooked proximalend 666 for engaging a hooked distal end 154 c of the articulation drivebar 154. An axial drive assembly 560 has a proximal pusher 614 forengaging the stapling drive shaft 148. Each of the stapling drive shaft148 and articulation drive bar 154 are driven by their respectiveoutputs from the motor assembly and, by virtue of the drive converterassemblies, are translated axially in a distal direction.

The axial drive assembly 560 has a stapling drive member or drive beam604 and clamping member 606 at a distal end of the drive beam 604. (SeeFIG. 8). The drive beam 604 may be an elongate sheet of material or aseries of stacked sheets of material. The clamping member 606 is amember that has an upper flange 606 b and a lower flange 606 c (see FIG.7) attached to a vertical portion 606 a that has a knife blade. Theclamping member 606 is attached to the drive beam or drive member 604 bywelding, adhesive, or some other method. The proximal portion of thedrive beam 604 has an opening for carrying the pusher 614 so that thestapling drive shaft 148 will drive movement of the axial drive assemblydistally. The clamping member 606 may have molded pieces of plastic, oranother plastic coating, for reducing the friction that will occurduring clamping and stapling. See EP 1,908,414 and U.S. Publication No.2008/0083812, the entire disclosures of which are hereby incorporated byreference herein.

A pair of jaws 506, 508 are attached to the elongate body 502 via amounting portion 572. A stapler anvil assembly 506 includes an anvil 512and cover 510. The anvil 512 defines a slot to allow the passage of theaxial drive assembly. The cartridge assembly 508 includes a staplecartridge 518, channel 516 and a firing assembly for interacting withthe drive beam 604 and clamping member 606. The channel has a ramped orsloping surface 516 a. The channel 516 also defines a slot (not shown)that allows the vertical portion 606 a to extend through the slot andlocate the lower flange 606 c below the channel 516. The staplecartridge 518 defines a plurality of staple slots 528 and a slot 526corresponding to the slots in the channel 516 and anvil 512.

The anvil assembly, cartridge assembly, or both, are pivotably movable.For example, the channel 516 has a proximal end with two holes 580 forreceiving bolts 582. The bolts extend through mounting assembly 572 sothat the cartridge assembly can pivot with respect to the anvilassembly. In this way, tissue can be clamped between the anvil assembly207 and the cartridge assembly 230.

Referring to FIG. 8, a mounting assembly 572 is pivotally secured to thedistal end of body 502, and is configured to be attached to the proximalends of the jaws of the loading unit 20 such that pivotal movement ofmounting assembly 572 about an axis perpendicular to the longitudinalaxis of housing portion 502 effects articulation of the pair of jaws.

Referring to FIG. 8, mounting assembly 572 includes upper and lowermounting portions 584 and 574. Each mounting portion includes a bore oneach side thereof dimensioned to receive bolts 582 for securing theproximal end of channel 516 thereto. A pair of coupling members 594engage the distal end of housing portion 502 and engage the mountingportions. Coupling members 594 each include an interlocking proximalportion configured to be received in grooves 598 formed in the housingportion 502 to retain mounting assembly 572 and body 502 in alongitudinally fixed position in relation thereto.

A pair of blow out plates 710 are positioned adjacent the distal end ofbody 200 adjacent the distal end of axial drive assembly to preventoutward bulging of drive assembly during articulation of the pair ofjaws. Each blow-out plate 710 includes a planar surface which issubstantially parallel to the pivot axis of the pair of jaws and ispositioned on a side of drive assembly to prevent outward bulging ofdrive member 604. Each blow-out plate includes a first distal end whichis positioned in a respective first groove formed in mounting assembly574 and a second proximal end which is positioned in a respective secondgroove formed in a distal end of housing 503 b.

Staples 530 are disposed in the staple slots 528 and are driven out ofthose staple slots by pushers 533. The vertical portion 606 a alsoextends through the slot in the anvil member 512 to locate the upperflange 606 b on an upper surface of the anvil 512. A sled 536 ispositioned in the staple cartridge initially in a proximal position, andhas wedges 534 that engage the pushers 533. The pushers have cammingsurfaces (not shown) so that as the sled 536 is advanced by the drivebeam 604 and clamping member 606, the sled will lift the pushers,driving the staples out of the slots 528, through tissue, and againststaple forming recesses in the anvil 512. As the drive beam 604 andclamping member 606 is initially advanced, the upper flange rides alongthe ramped surface 516 a to approximate the anvil assembly 506 with thecartridge assembly 508. As the staples are fired, the drive beam 604 andclamping member 606 continue to engage the anvil assembly and cartridgeassembly to maintain the position of the anvil assembly and cartridgeassembly during firing of the staples.

The loading unit 20 can include a first data connector for connectionwith a second data connector on the adapter assembly 100, to feed databack to a controller 9 in the handle portion 10. The first dataconnector can comprise a contact or contacts on the body 200 of theloading unit, whereas the second data connector can be one or morecontacts arranged on the adapter assembly 100 to connect with thecontacts of the first data connector. A memory unit is disposed in theloading unit and is connected to the first data connector. The memoryunit can comprise an EEPROM, EPROM, or the like, contained in the body200 and can hold information such as the type of loading unit, the sizeof the staples in the loading unit, the length of the staple line formedby the loading unit when the staples are fired, and information aboutwhether the loading unit has already been fired. The second dataconnector is connected to the controller 9 in the handle assembly bywires, or leads, that extend through the adapter assembly, or viawireless connection. Alternatively, the memory unit of the loading unitcan communicate wirelessly with the controller in the handle portion.

The memory unit can store the end of stroke of the axial drive assembly,or the length of the stroke, for the loading unit. This information canbe used by the controller 9 to avoid over driving the axial driveassembly, which can damage the loading unit. In this way, the controllercan receive the end of stroke or stroke length information, and halt thedriving of the stapling drive cable 134 when the end of the stroke isreached. Alternatively, the controller 9 can be configured to detectwhen the axial drive assembly has reached the end of the stroke, and hasfired all the staples in the staple line. The controller detects this,using sensors in the loading unit, or by monitoring the current in themotor assembly. For example, when the current in the motor assemblyincreases dramatically, or spikes, the operation of the motor assemblyis halted.

The controller 9 can be an integrated circuit, analog or logiccircuitry, and/or microprocessor, or an array of such components. Thecontroller receives information from the loading unit memory unit, othersensors in the adapter assembly and/or loading unit, and can control theoperation of the surgical device. For example, sensors can be used todetect the clamping forces at the cartridge assembly and anvil assembly.The controller can initiate a visual or audible alarm in the event thatrecommended forces are exceeded, or the controller can cease operationof the surgical device by halting the motor of the handle assembly. Aremovable memory chip or card can also be included.

Where loading units 20 having different staple line lengths areavailable for use with the surgical device, identifying the length ofthe staple line and using that information to control the operation ofthe surgical device can be useful. For example, the controller 9receives the staple line length from the memory unit and through thefirst data connector on the loading unit. That information is comparedwith data from the memory unit 11 in the handle portion 10 to determinehow far to drive the staple drive shaft 148 and avoid driving that shaft148 too far, and potentially damaging the loading unit. The type ofloading unit, and the staple line length, staple size, etc., cantherefore be used to control the operation of the surgical device. Thecontroller 9 can be programmed to reverse the direction that thestapling drive cable 134 is driven after the staple line length isreached, thereby reversing the direction of the stapling drive shaft 148and allowing the jaws of the loading unit to open. Alternatively oradditionally, sensors can be provided in the loading unit to determinethe position of the sled 536, clamping member 606, and/or drive beam604, and to reverse the direction of the motor when the end of thestaple line has been reached.

The handle portion 10 supplies power to the motor assembly 5 through abattery, generator, or electrical socket in order to drive the rotationof the cables 134, 136. The amount of torque required to clamp the jawsof the loading unit onto tissue can be sensed, by monitoring the motorcurrent. During clamping of tissue, during the initial movement of theclamping member 606 over the ramped surface 516 a of the channel 516,the clamping member 606 exerts forces on the channel 516, and on thetissue being clamped between the cartridge assembly and anvil assembly.These forces can be detected by the controller 9, and characterized. Forexample, the force of the cartridge assembly in clamping tissue againstthe anvil 512 can be detected and compared to data in the memory unit 11of the controller, and used to provide information to the surgeon. Also,this information can be saved and reported for later use. The handleportion 10 desirably has a display unit and/or indicator for displayinginformation or alerting the user of the surgical device. Additionally oralternatively, the device can include an audio component for sounding anaudible alarm or recorded message. The display can be a light emittingdiode, liquid crystal display or any other display.

An encoder or encoders can be used as one or more of the sensors of thesurgical device. The encoder includes Hall effect devices mountedadjacent the drive shafts from the motors, to detect a magnet or magnetsmounted on the shafts. In this way, the angular position of the driveshafts and their direction, as well as the position of the drive shafts,drive cables 134, 136, articulation drive bar 154, and/or stapling driveshaft 148 can be determined. It is contemplated that, in any of theembodiments disclosed herein, there are encoders or other sensorsprovided for the drive cables 134, 136, articulation drive bar 154,and/or stapling drive shaft 148. In any of the embodiments disclosedherein, current draw characteristics from the battery or batteries, andfrom the one or more motors of the motor assembly 5 are sensed. Otherstrain, force, and/or positional sensors in the end effector, adapterassembly, and/or handle portion are contemplated.

Sensors 211 can also be provided in the loading unit 20 to determine thegap between the staple cartridge 508 and anvil 512. The controller 9 caninclude tables of information that indicate the desired gap for aparticular loading unit (based on staple size, staple line length, etc.)and can be used to prevent the firing of staples in the event that thedesired gap cannot be achieved. For example, U.S. Patent Publication No.2012/0211542, the entire disclosure of which is hereby incorporated byreference herein, discloses tissue management modes for controlling asurgical device and utilizes stored correlation tables. In any of theembodiments disclosed herein, the surgical device can include acontroller and sensors in the adapter assembly 100, loading unit 20,and/or handle portion 10 that determine the clamping force, the gapbetween the cartridge 508 and anvil 512, whether the loading unit hasbeen used, the type of loading unit, and/or the staple line length orsize. The information is used to control the operation of the surgicaldevice, provide some indication to the user, and/or is simply stored forlater use.

In any of the embodiments disclosed herein, the loading unit has amechanical feature for determining the type of cartridge 220, the stapleline length, size of the staples, etc. The mechanical feature is aspecially shaped bump, depression, or series of bumps or depressions,that are unique to that type of loading unit. The mechanical feature canhave different shapes and/or textures, can determine staple size, stapleline length, or both. It can also be used to determine other aspects ofthe loading unit, such as whether it is articulating ornon-articulating, or whether a buttress material is being used. Themechanical feature can be a coating on the loading unit, that providestexture, a different frictional resistance, or some other aspect thatcan differentiate the type of loading unit.

The mechanical feature 1020 is located on the loading unit at a locationwhere the clamping member 606 engages the cartridge assembly 508, anvilassembly 506, or both. As shown in FIG. 9, a loading unit 1001 has ananvil assembly and cartridge assembly 1230. In the initial advancementof the clamping member 606, which can be the clamping member shown inFIGS. 6, 7 and 8, the clamping member lower flange 606 c traverses theramped surface 516 a. Then, the clamping member proceeds to move downthe surface of the channel 1516, as driven by the staple drive member148. The mechanical feature or features 1020 provided on the channel1516 change the force or torque at the motor. The change in force ortorque is detected by the controller 9 of the handle portion andcompared to data in the memory unit 11 of the controller. The end ofstroke 1040 for the particular loading unit 1001 is determined. Usingthis information, the controller 9 determines that the loading unit 1001has, for example, a 60 millimeter staple line length, and drives thestapling drive cable 134 a predetermined number of rotations, to drivethe stapling drive shaft 148 the distance necessary for driving all ofthe staples, but not exceeding the length of the cartridge assembly.

For example, the linear force can be determined utilizing motor current,motor current limits, and/or revolutions per minute. Alternatively,strain gauges can be used. These measurements can be taken with sensorsin the end effector, adapter assembly and/or handle portion.

In addition, it can be determined that the loading unit is anarticulating loading unit, allowing the articulation drive cable 136 tobe driven. If it is determined that the loading unit is not anarticulating loading unit, the articulation drive cable 136 is preventedfrom being driven by not turning on the corresponding motor in the motorassembly 5. For example, a mechanical feature or features 1020 can beprovided on the anvil 512 that identify the type of loading unit, stapleline length, staple size, or identify the loading unit as articulating.Similarly, a mechanical feature or features 1020 can be provided on thechannel 1218 and/or anvil surface that identify the loading unit ashaving a buttress preloaded onto the loading unit, or identify theloading unit as one that has a dissecting tip.

In any of the embodiments disclosed herein, the mechanical feature 1020can be provided on the anvil assembly, cartridge assembly 1230, or both,in a pattern of recesses, protrusions, hills, valleys, or somecombination of the foregoing. The physical features of the pattern ofmechanical features 1020 change the force or torque at the motorassembly and are detected at the controller. In certain embodiments, themechanical features 1020 have a first pattern 1020 a and a secondpattern 1020 b. Two or more different patterns can be used, to expandthe number of different loading units 1001 that can be indicated. Inaddition, the pattern or a change in the pattern of mechanical features1020 can be used to indicate that the clamping member 606 is reachingthe end of stroke 1040. The controller can be configured (programmed orstructured or the like) to monitor the change in force or torque, anddetermine when the operation of the motor assembly 5 should be arrested.In this way, the driving of the axial drive assembly is halted beforethe axial drive assembly reaches the end of stroke 1040. For example, asshown in FIG. 9, the mechanical features 1020 have a first pattern 1020a and a second pattern 1020 b that are different from each other in thatthey have different recesses or protrusions. For example, first pattern1020 a has recesses or protrusions that are longer in length than therecesses or protrusions of the second pattern 1020 b. The controller isconfigured to determine the end of stroke 1040 for the particularloading unit 1001 based on the change in the torque or force detected bythe controller. The velocity of the movement of the clamping member, aswell as its position, can be determined, based on the indicationprovided by the mechanical feature.

For example, the loading unit 1001 has a cartridge assembly 1230 with astaple cartridge that defines a longitudinal axis X as shown in FIG. 9.The axial drive assembly is driven through the staple cartridge to firethe surgical staples as discussed above, in the longitudinal directionalong the axis X. As the axial drive assembly is driven, the clampingmember 606 lower flange 606 c engages the channel 1516 and anymechanical features 1020 provided on the channel 1516. In this way, thelower flange 606 c engages the first pattern 1020 a of mechanicalfeatures first, and then engages the second pattern 1020 b of mechanicalfeatures. The second pattern 1020 b of mechanical features is disposedcloser to a distal end of the channel 1516, and closer to the end ofstroke 1040.

The channel 1516 defines a slot 1517 to allow the vertical portion 606 aof the clamping member to pass through the slot 1517 so that the lowerflange 606 c can engage the channel 1516. A distal end of the slot 1517is defined in the channel, and forms the end of stroke 1040. Attemptingto drive the axial drive assembly past the distal end of the slot 1517,past the end of stroke 1040, can result in damaging the loading unit1001, the adapter assembly, components of the handle assembly, etc.

In any of the embodiments disclosed herein, electronic sensors, opticalsensors, magnetic sensors, and/or any other kind of sensors, can be usedin addition to the mechanical feature 1020 to provide information aboutthe particular loading unit and its use. In any of the embodimentsdisclosed herein, an electronic sensor, magnetic sensor, optic sensor,or other sensor, is provided on the upper flange 606 b, anvil 512,channel 516, or any combination thereof, to indicate the type of loadingunit, staple size, staple line length, other aspects of the loadingunit, and/or whether the loading unit has been fired or previously used.

In any of the embodiments disclosed herein, the adapter assembly caninclude a sensor or identification chip, for any of the purposesdiscussed herein, including for identifying the type of adapter assemblyor characteristics thereof. Electronic sensors, optical sensors,magnetic sensors, and/or any other kind of sensors can be used.Desirably, the sensor or chip communicates with the controller, whichmay be located in the handle portion, through wires or leads, or throughwireless communication.

The sensors provided may include, in any of the embodiments disclosedherein, temperature sensors for measuring the internal temperature in oraround the surgical device.

The controller comprises one or more microprocessors or chips, asdiscussed above. The controller can comprise more than one such chips orprocessors, and can be an array of such elements. Data for determiningthe type and characteristics of end effectors, adapter assemblies and/orhandle portions can be stored in memory units in the form of graphs,charts, tables, arrays, or the like. This can be used in conjunctionwith other systems provided for the surgical device.

Furthermore, the circular stapling loading unit 30 and transversestapling loading unit 40 have driver members like the clamping member606 and drive beam 604 described above that can be used with mechanicalfeatures 1020 to determine the type of loading unit, size of staples,length or diameter of the staple line, etc. Mechanical features on thedriven elements of these stapler components can be used to identify theinformation discussed herein.

Information communicated through a feedback loop of the controller canbe used to determine functional modes for each unique end effector,adapter assembly, and/or handle portion. Based on an end effector orloading unit ID and current firing conditions, performance of the systemcan be dynamically adjusted to achieve improved outcomes. These settingscan be pre-determined or intelligently adapter by the controller duringoperation.

One example implementing this would be adjusting the torque output whenan unknown buttress material was detected to be in use.

The mechanical features can be located in a variety of positions.Examples can include, but are not limited to the following.

In a circular stapler device, such as an EEA stapler, the mechanicalfeatures are provided along any component or components which moveduring operation. Mechanical features can be formed on the clamp shaftand/or staple shaft. The clamp shaft has the largest stroke and can beused to collect both positional information and force information. Forexample, the controller could monitor how a component deforms under theapplied load and measuring this deformation using the feedback loopsensors and the controller.

In a linear endoscopic device, such as an Endo GIA stapler, the locationof the mechanical features in the end effector or loading unit caninclude, but is not limited to, mechanical features on the sides of thedrive beam, which would be read by a sensor as they pass. This patterncan be applied symmetrically on both sides, or asymmetrically toincrease bandwidth of the signal.

Mechanical features on the top and or bottom of the knife bar (see FIG.10) can be such that a sensor can detect the features along the surface.The drive bar may have a plurality of openings or windows which can beused in lieu of or in addition to mechanical features. A conventionalphysical sensor, or a photocell, could be used to determine such windowshave passed, or how many have passed, or how quickly they have passed.In any of the embodiments disclosed herein, a conventional physicalsensor, or a photocell, could be used to determine that the mechanicalfeatures have passed, and/or how many have passed, and/or how quicklythey have passed.

Furthermore, the bottom portion of the clamping member, the lower flange606 c, or a separate member that forms the bottom portion, can includethe mechanical features. Such mechanical features can be on the surfacethat engages the channel, or on the sides of the flange. The channelitself could include mechanical features, or the sides of the drive beamcan include such features. See FIGS. 10A and 10B. The loading unit mayinclude a sensing member 2001 being attached to the loading unit housingat one end, and having an opposite free end 2003. The member 2001 isflexible and includes a protrusion 2005 on the free end 2003. As thedrive beam or member 2560 is advanced through the staple cartridge andanvil, the protrusion interacts with mechanical features 2020 on thedrive beam. As shown in FIG. 10B, the mechanical features 2020 may berecesses on the drive beam. In other embodiments, a photocell or othersensor detects, counts, records, or otherwise recognizes the mechanicalfeatures as a means to identify the loading unit, characteristicsthereof, the end of stroke, and/or the velocity of the drive bar. Theremaining components of the loading unit having the drive beam 2560 canbe as described above in connection with loading unit 20.

While the present invention has been described and illustrated inconnection with certain embodiments, it is not the intention of theapplicant to restrict or in any other way limit the scope of the claimsto such detail. Additional advantages and modifications will be readilyapparent to those skilled in the art.

What is claimed is:
 1. A loading unit for a surgical stapling device,comprising: a cartridge assembly and an anvil assembly, the cartridgeassembly including a channel and a staple cartridge having a pluralityof surgical staples therein; an axial drive assembly with a clampingmember, the clamping member having an upper flange for engaging theanvil assembly, and a lower flange for engaging the channel, the axialdrive assembly being movable through the staple cartridge to drive thestaples out of the staple cartridge and against the anvil assembly; andmechanical features defined in the channel for indicating an end ofstroke for the axial drive assembly, the mechanical features having afirst pattern and a second pattern.
 2. The loading unit according toclaim 1, wherein the staple cartridge has a plurality of stapleretaining recesses and the surgical staples are disposed in the stapleretaining recesses.
 3. The loading unit according to claim 2, whereinthe staple retaining recesses are arranged in linear rows.
 4. Theloading unit according to claim 1, wherein the axial drive assemblyincludes a drive beam.
 5. The loading unit according to claim 1, furthercomprising a sensor for determining a gap between the anvil assembly andthe cartridge assembly.
 6. A surgical stapling device, comprising anelongate portion and a loading unit according to claim
 1. 7. Thesurgical stapling device according to claim 6, further comprising ahandle portion.
 8. The surgical stapling device according to claim 7,wherein the handle portion has a motor assembly.
 9. The surgicalstapling device according to claim 8, further comprising a controller.10. The surgical stapling device according to claim 9, wherein thecontroller is configured to determine the end of stroke.
 11. Thesurgical stapling device according to claim 10, wherein the firstpattern of mechanical features has mechanical features of a differentsize than a size of the mechanical features of the second pattern. 12.The loading unit according to claim 1, wherein the staple cartridgedefines a longitudinal axis and staple retaining recesses arranged inlinear rows along the longitudinal axis.
 13. The loading unit accordingto claim 1, wherein the channel defines a slot.
 14. The loading unitaccording to claim 13, wherein a distal end of the slot forms the end ofstroke.
 15. The loading unit according to claim 14, wherein the secondpattern of mechanical features is closer to the distal end of the slotthan the first pattern of mechanical features.
 16. The loading unitaccording to claim 1, wherein a light sensor detects the mechanicalfeatures.